Waiczies, Sonia

Our group uses magnetic resonance imaging (MRI) to study inflammation and anti-inflammatory drugs in vivo. We seek to better understand the kinetics and dynamics of immune cell invasion during inflammation within the central nervous system (CNS). For instance, brain inflammation in multiple sclerosis involves immune-cell recruitment during the early pathogenic stages before clinical symptoms appear. The blood-brain barrier (BBB) restricts migration of immune cells to the CNS, but during inflammation the BBB is altered.
Fluorine imaging: We employ fluorine MR methods to study inflammation and anti-inflammatory drugs in vivo. We label immune cells with fluorine (19F) for MRI detection. Immune cells are labeled with perfluorocarbon (PFC)-rich particles and are then injected in vivo to be tracked by 19F MRI. 19F MR images are co-registered with conventional proton (1H) MRI. Detection of contrast-enhancing lesions by MRI at the site of BBB disruption with contrast agents such as gadolinium permits correlating the disruption with active inflammation. However, gadolinium extravasation does not provide direct evidence of immune cell CNS trafficking and may occur independent of lesion formation. We are developing novel MRI techniques to gain a more accurate and comprehensive view of CNS inflammation.
To make fluorine MRI possible even in situations where the availability of fluorine is very low, we employ various strategies that boost signal-to-noise ratio (SNR). One strategy is to increase the availability of fluorine e.g. increasing the uptake of fluorine rich nanoparticles by immune cells. Another strategy is use higher magnetic field strengths. We are cooperating with the US National High Magnetic Field Laboratory (MagLab), which is supported by the State of Florida and the National Science Foundation to perform 19F MR measurements. By using cryogenically-cooled coils we can also boost SNR and be able to perform MRI microscopy. Cryogenically-cooled coils are made of superconducting material with decreased coil resistance and thermal noise and thereby increased SNR. Micro MRI enables imaging with a spatial resolution less than 100µm. These coils provide detail in anatomical morphological changes (1H MRI) as well as inflammatory information (19F MRI).